Petitioner, Niles Jackson, the announced winner at the general election held on November 6, 1990, for office three, district judge, seventh judicial district, Oklahoma County, requests us to assume original jurisdiction and issue certain writs of mandamus. He asks us to issue a writ of mandamus to Respondent, the Honorable John Maley, trial judge over a petition alleging irregularities filed by Respondent, Wendell Smith (announced loser of the election), directing him to deny the petition. The trial judge in ruling on Smith’s petition held it could not be determined with mathematical certainty which candidate was entitled to a certificate of election and he entered judgment ordering a new election. Jackson also asks for writs of mandamus to the Oklahoma State and County Election Boards directing them to issue him a certificate of election to the contested office. The secretaries of the election boards, Lance Ward and Marti L. Hayes, respectively, have been named as Respondents.1 Recognizing the great public importance of election matters we assume original jurisdiction under OKLA. CONST, art. VII, § 4 and cases such as Keltch v. Alfalfa County Election Board, 737 P.2d 908, 909 (Okla.1987) and Helm v. State Election Board, 589 P.2d 224, 226 (Okla.1979). We further vacate the judgment of the trial judge.
After the election Jackson was the announced winner by 157 votes according to the official canvass generated by the Oklahoma County Election Board.2 He had 68,-004 votes to Smith’s 67,847. Smith attempted to impeach the official canvass by showing there were a sufficient number of irregularities so that it was impossible to determine with mathematical certainty which candidate was entitled to be issued a certificate of election.3 The trial judge ruled he carried his burden to so show. We hold the trial court erred.
The judgment of the trial judge is broken down into three parts. The first part finds certain irregularities which the trial judge ruled established it could not be determined with mathematical certainty which candidate was entitled to a certificate of election. Such determination in an irregularity matter is required by statute. 26 O.S.Supp.1990, § 8-120(2). The burden of establishing same is upon the contestant, here Smith. Groves v. Bumgarner, 662 P.2d 307, 308 (Okla.1983); Helm v. State Election Board, supra, 589 P.2d at 227; Hembree v. City of Stilwell, 597 P.2d 1218, 1220 (Okla.1979). These irregulari*614ties found by the trial court are as follows. (1) 87 persons who voted at the election in Oklahoma County were shown to not be registered to vote by the records of the Oklahoma County Election Board; (2) 77 ballots cast at the election were not read by the electronic scanning (counting) devices used by Oklahoma County to count the ballots;4 (3) 66 more votes were cast than persons signing the official precinct poll books, challenged voter and absentee voter affidavits; and (4) one person voted at two different precincts.
The trial judge next found a series of irregularities he said “cast serious doubt as concerns the mathematical certainty of the election_” These were as follows. (1) 587 spoiled ballots were issued without proper affidavits;5 (2) at precinct 225 there was a lack of control over the ballots and voters were not allowed to place ballots in ballot boxes of any type, but were instructed to leave them on a table in open view; (3) there were numerous head errors pertaining to the electronic scanners; (4) there were numerous problems with the electronic scanners; (5) there were several electronic scanning tapes (precinct vote total tapes) which did not have a zero tape attached; (6) numerous accounting errors on the precinct ballot accounting forms exist which means all ballots were not accounted for by precinct officials; and (7) there was a lack of proper marking equipment, to wit: specialized pens which allow the scanner to properly record the vote.
The third category of irregularity concerned the trial judges “questioning” of whether the election results were reversed, i.e. that Smith really won by 157 votes, rather than Jackson. However, no finding was made by him the results were so reversed and as we shall demonstrate the evidence in this record does not support such a conclusion. Instead, the evidence unequivocally refutes it. We shall discuss the various irregularities found by the trial court and their impact, if any, on this election.
In order for an irregularity to establish it is impossible to determine with mathematical certainty which candidate was the winner a contestant must make a prima facie case of mathematical uncertainty. See Helm, supra, 589 P.2d at 228. Only then does it become incumbent on the announced winner to go forward with the evidence to establish he achieved victory by a mathematical certainty. Id. This is so because a contestant in Smith’s position must present at least enough evidence to impeach the correctness of the precinct returns, as embodied in the official canvass of the county election board, which are prima facie evidence themselves of the correctness of the vote. To so impeach the precinct returns a contestant must, at *615least, make a showing either illegal votes were cast or votes were cast by legal voters that should have been counted, but were not, or were counted incorrectly, in sufficient numbers, to eliminate his opponent’s margin of victory. See Hembree, supra, 597 P.2d at 1220; see also Helm, supra, 589 P.2d at 227-228. He could also show some other irregularity, such as legal voters, again in sufficient numbers, were denied the right to vote. He must make such a showing because courts indulge every presumption in favor of the validity of an election and, where possible, that validity will be sustained. Keltch, supra, 737 P.2d at 911. Mere probabilities will not suffice to carry this initial burden. Groves, supra, 662 P.2d at 308. From our review of this record we find only two of the trial court’s rulings arguably meeting the prima facie standard, but the number of votes involved are wholly insufficient to eliminate Jackson’s margin of victory. Thus, the trial court erred in his determination to order a new election.
Oklahoma County has over 280 precincts within its boundaries. During the general election over 172,000 votes were cast in the county of which over 135,000 were cast in this race. To vote at a precinct the person presenting himself on the day of the election must be a registered voter. To determine if one is registered precinct officials are provided with a precinct registry (poll book) which is compiled by the county election board and provided to the precincts. 26 O.S.Supp.1990, § 7-102.1 and § 7-114. Voters in the registry are required to sign it when they present themselves to vote. 26 O.S.Supp. 1990, § 7-117. Persons not listed in the registry, but who present themselves to vote may still east a ballot if they present a voter identification card and sign an affidavit swearing that he/she is a registered voter of the precinct and no absentee ballot has been cast. 26 O.S.Supp.1990, § 7-116. The first irregularity found by the trial court concerns these latter voters. He ruled 87 of these voters, at the time of hearing, were not shown to be registered in the records of the county election board. Clearly our case law supports the view that the vote of an unregistered voter is illegal and should be discarded. Baggett v. State Election Board, 501 P.2d 817 (Okla.1972). Our review of the record bears out this finding of the trial court, but the 87 votes alone are insufficient in numbers to meet the prima facie case for Jackson’s margin of victory was 157 votes according to the precinct returns.6
The trial court also found one person voted at two different precincts. The record bears out this finding. Documentary evidence was provided a person with the exact same name and address voted at the two precincts, apparently at one by signing a challenged voter affidavit. Although Jackson argues it simply could have been a case of two different voters with the exact same name and address (e.g. father and son) we believe a prima facie case was made by contestant as to the voter being the same person. No evidence was introduced by Jackson to refute the prima facie case and we, thus, discard the two votes cast by this individual.
The next categories of votes we will discuss concern the 587 spoiled ballot affidavits and the finding of the trial court 66 more votes were cast than signatures in the poll book, challenged voter and absentee voter affidavits. We discuss these two *616categories together because we believe both categories are similar to the extent they are matters of a directory nature insufficient to invalidate any votes in the numbers claimed by contestant.
Our case law recognizes election irregularities- will not always invalidate the result of an election. Although irregularities of any kind should not be permitted by election officials “whether an irregularity or several irregularities void an election depend upon the circumstances in each particular case.” Edmondson v. State ex rel. Phelps, 533 P.2d 604, 613 (Okla.1974). Further, we have recognized provisions of our election laws are mandatory if sought to be enforced before an election, but after an election they normally should be held to be directory only, unless of a character to effect an obstruction to the free and intelligent casting of the vote or the ascertainment of the result, or the provisions affect an essential element of the election or unless it is expressly declared in the statute that the particular act or its omission is essential to the validity of the election. See Town of Grove v. Haskell, 24 Okla. 707, 104 P. 56, 61 (1909), citing with approval Jones v. State ex rel. Wilson, 153 Ind. 440, 55 N.E. 229 (1899) and Edmondson, supra at 614-615. As to 587 spoiled ballot affidavits not being signed and 66 more votes being cast than supporting poll book signatures, challenged voter and absentee voter affidavits our view is these matters are insufficient to invalidate the election or the votes claimed because they concern only directory provisions.
The signing of a spoiled ballot affidavit is clearly required by our statutes when a voter somehow spoils a ballot such that a new one has to be issued. 26 O.S. 1981, § 7-122. However, § 7-122 provides no invalidating sanction for violation of the provision and the evidence here, other than the failure to sign the affidavit, provides no indication the spoiled ballots were not destroyed as required by § 7-122 or that any of the spoiled ballots were counted as valid votes at the election. Neither does the fact new ballots were issued support the conclusion, as Smith seems to assert, that some of the ballots were voted by unregistered voters. Although this is a possibility, just as anything is a possibility, to conclude some or all of these ballots were voted by unregistered people involves nothing more than unwarranted speculation, speculation we refuse to engage in here. In fact, certain report forms from precinct officials to the county election board introduced into evidence and testimony from election officials would indicate the contrary. This evidence was to the effect that many times an individual voter spoils more than one ballot while attempting to cast a valid vote and because of either embarrassment, the hectic pace on election day or some other innocent reason the voter does not sign an affidavit.
In Oklahoma County the record shows over 9,000 spoiled ballots were involved. Although we believe the failure to obtain signatures for the issuance of almost 600 new ballots for the spoiled ones is an irregularity and violation of § 7-122 it is only in the realm of speculation (i.e. the realm of the possible) that any of the 587 instances resulted in an illegal vote being cast or counted at this election. Thus, no prima facie case of mathematical uncertainty was made out by Smith in regard to the spoiled ballot affidavit issue sufficient to overcome the presumption in favor of the precinct returns as correctly reporting the votes for this election.
The issue concerning 66 more votes being cast than signatures in the poll books, challenged voter and absentee voter affidavits, we believe, may be looked at in the same manner as the 587 spoiled ballot affidavits. Voters, before voting, are re-qüired by statute to either sign the precinct registry (poll book) [26 O.S.Supp.1990, § 7-1171], a challenged voter affidavit [26 O.S.Supp.1990, § 7-116] or, when a voter has requested an absentee ballot but has not voted it, an absentee voter affidavit [26 O.S.1981, § 7-115]. The trial court found the number of signatures on these documents was 66 less than the total votes cast in Oklahoma County. The signing of these documents is, in our view, directory only and to discard these 66 votes, as with *617587 spoiled ballot affidavits, would force us to engage in nothing more than speculation that one or more of the votes was somehow tainted with illegality. We will not engage in such speculation.
In Coffey v. Board of Commissioners of McCurtain County, 205 Okla. 238, 237 P.2d 139, 142 (1951), we ruled absence of a poll book was immaterial when election challengers sought to examine it to determine whether unqualified electors had been allowed to vote. This was a recognition that signing the poll book, although required by statute, was directory in nature only. More recently, we made clear in Keltch v. Alfalfa County Election Board, supra, 737 P.2d at 910, signing a poll book was directory. There we held although there were four more ballots issued than signatures in the poll book (and the margin of victory was three votes) such was insufficient to void the election result.7 These cases are dispositive of the issue of whether more votes being cast than signatures on the involved documents is sufficient to discard 66 votes. Without additional proof any of the votes were unlawful or illegal in some regard (something not shown by this record) the failure to obtain signatures cannot itself support a conclusion they were illegal. Although we do not look lightly on the election officials’ apparent failure to obtain signatures for each vote cast the signature requirement being directory only is not of such a character to taint those votes or discard them here to support Smith’s prima facie case of mathematical uncertainty.
The next irregularity found by the trial court pertinent here is the finding 77 ballots were not read by the electronic scanning (counting) device used by Oklahoma County to count the ballots. In that this issue is intertwined with the trial court’s findings of head errors and problems with the electronic scanning devices we will discuss these matters together.
To intelligently consider these issues it is necessary to understand the basic working of the electronic voting devices' used in Oklahoma County. A voter fills out a cardboard ballot with a specialized pen8 and inserts the ballot into the machine. The device is equipped with a scanner that reads the choices made. In certain instances the device is programmed to return or “kick back” a ballot to the voter. Some examples of. when a ballot would be “kicked back” are when a totally blank ballot is inserted, when the ballot is not fed into the device properly or when certain portion(s) of the ballot have been ripped or torn. Each time a ballot is “kicked back” the counting device is programmed to register a not defined ballot or error. These not defined readings or “kick backs” for this election totaled over 1300. Although the supervisor of the voting machine division testified this number was highly unusual or irregular his testimony made clear *618in each instance when a not defined error was registered the ballot was “kicked back” to the voter and, accordingly, an opportunity was given for the ballot to be reinserted and counted correctly.9 Further, if the machine again registered it as not defined it would again be “kicked back” to the voter as many times as the machine would not read it. From our review of the record, these not defined ballots or errors registered each time a ballot is returned to a voter were primarily the head errors or scanning problems referred to by the trial court.10 Rather than indicating an irregularity or malfunction of the machine, what they truly indicate is the machine working as it was designed when a ballot cannot be read. In each instance the voter is afforded an additional opportunity to reinsert his ballot into the machine correctly to be counted or if the machine refuses to accept it after repeated attempts the voter would obviously be afforded an opportunity to obtain a new ballot to vote that can be read by the electronic scanning device. Thus, the purported head errors and scanning problems found by the trial court afford no basis to question the accuracy of the precinct returns because no evidence was presented these supposed problems resulted in any voter being denied the right to vote or that any validly marked ballot was not counted.
In contrast to the not defined ballots or errors, the 77 unread ballots out of over 170,000 cast are ones permanently recorded for this election as unread and are the product of pushing an override button on the machine which will allow the device to accept the ballot for deposit in what the voting machine division supervisor referred to as an out-stack area. In other words, the only way a ballot can be run through the machine and registered as permanently unread is by manual manipulation of the device through the use of the override button. Although the record contained each and every precinct where such unread ballots were recorded Smith failed to call any precinct officials in those precincts to detail the circumstances surrounding the reason for the pushing of the override button to accept the ballot as unread. In the absence of evidence that any of said ballots should have been registered as anything but unread we believe no basis exists to find that they should have been read because there is no indication they were properly voted ballots entitled to be counted. This is particularly so when one considers certain testimony of the voting machine supervisor.
The supervisor testified that many times during elections voters will present themselves to vote, they will sign the poll book and insist that precinct officials make the machine take their ballot even though it is blank. Remember, a totally blank ballot will not be accepted by the device, but will be returned to the voter. In other words, these 77 ballots may have merely been a form of protest by some voters who insist their ballots be counted as unread and a vote for no one. We, thus, find unpersuasive the argument these 77 unread ballots may be viewed as adding to Smith’s prima facié case to void this election because of mathematical uncertainty.
Other irregularities found by the trial court that he indicated cast serious doubt as concerns the mathematical cer*619tainty of the election, as opposed to proving it is impossible to determine the winner with mathematical certainty as is required by 26 O.S.Supp.1990, § 8-120, may be dealt with as a group. These concern lack of control over the ballots at precinct 225, errors by precinct officials in the ballot accounting forms, a lack of proper marking equipment to allow the scanning device to properly record the vote and several electronic scanning tapes (precinct vote total tapes resembling adding machine tapes) did not have an initial zero tape attached to them as the rules of the State Election Board require.11 As to all four of these irregularities there is not one shred of credible evidence in this record they resulted in any eligible voter being denied the right to vote, that ballots cast were not properly recorded or that any ballots were cast by anyone other than qualified electors. Although there is speculation in the record that it is possible such could have occurred, speculation as to mere possibilities simply does not suffice to overcome the presumption in favor of the validity of this election or the results as reported by precinct officials. As we noted earlier, we will not engage in such speculation and void this election merely because irregularities are shown. The irregularities must be shown by Smith to make it impossible to determine with mathematical certainty who is entitled to a certificate of election. See Edmondson v. State ex rel. Phelps, supra, 533 P.2d at 616. The irregularities noted do not so show.12
The last matter “found” by the trial court was to the effect of his questioning whether the results reported from the various precincts were somehow backwards or reversed because of a mispro-gramming of the electronic scanning device. The argument supporting this questioning is that because the first name on the ballot (here Smith) is apparently to be recorded on the official canvass of returns generated by the county election board in the 03 column and the first name in this race was recorded in the 04 column the results from the various precincts could have been reversed. From our review of the record the trial court and Smith misper-ceive the evidence. What the evidence shows, at most, was that the names of these two candidates on the official canvass as reported by Oklahoma County were reversed from how they appeared on the ballot, not that the results were reversed. It is clearly shown by review of certain totals tapes generated at three precincts directly from the electronic voting devices used at these precincts which were admitted into evidence, that the number of votes for each respective candidate shown on these tapes exactly match the number of votes recorded on the official canvass of returns generated by the county election board for said precincts. Thus, although the names on the official canvass are reversed from how they appear on the ballot and on the totals tapes the results themselves are correctly reported on the official canvass and nothing in this record shows otherwise. Therefore, the trial court’s questioning in regard to this issue provides no basis to void this election or order a new election for the involved office.13
*620Generally, in the absence of fraud or corruption and in the presence of merely statutory informalities, the results of an election will not be invalidated. See Cooper v. Dix, supra 771 P.2d at 617. No fraud or corruption is involved here. Further, when irregularities are shown to exist, but they are not of such a character in either quality or quantity to prove the outcome of an election cannot be determined an election result will be upheld. This view is based on the rationale of the electorate in having its votes counted and, secondarily, the expense involved in a new election. Our review of the instant record convinces us there is no basis to void this election or thwart the will of the electorate as reported by the various precinct returns in Oklahoma County.
Accordingly, the decision of the trial court is VACATED. In that Respondents Ward and Hayes have supported the position of Jackson in this original action we deem it unnecessary to issue a writ of mandamus to them requiring the issuance of a certificate of election to Jackson. We assume in light of our opinion a certificate will be so issued without the requested writ.
SIMMS, HARGRAVE and SUMMERS, JJ., concur. KAUGER, J., concurs specially. HODGES, V.C.J., concurs in part, dissents in part. OPALA, C.J., dissents. DOOLIN, J., disqualified.. Respondents Ward and Hayes support the position of Petitioner in this original action. They request, as does he, that we assume original jurisdiction and rule Respondent Smith failed to establish sufficient irregularities to void the election. They, thus, take the position the trial judge was in error when he so ruled and in ordering a new election be held.
. The canvass of precinct returns is generated by a county election board from the precinct returns of the county. 26 O.S.1981, § 7-136. It is used by the Oklahoma State Election Board to certify the results of the election for all state officers and questions. Id.
. Respondent Smith alternatively requested in his irregularity petition that he be certified as the winner of the election. The trial judge did not order such relief nor does Smith press said claim for relief here. Therefore, our opinion is limited to a determination of whether sufficient irregularities were shown to exist to support the trial court’s decision to void the election result and order a new election. Also not before us in this case is a trial court ruling on a petition for a recount filed by Respondent Smith. The trial court ruled in such regard a recount could not take place because the ballots, after the election, had not been preserved in the manner and by the officers prescribed by law such that it was not possible to determine (1) whether the ballots were the identical ones cast by the voters and (2) that the ballots had not been exposed to the reach of unauthorized persons such as to afford a reasonable opportunity of their having been changed or tampered with. Under 26 O.S. 1981, § 8-112 such determinations are required to be made before a recount may take place and if they cannot be made by the trial judge no recount takes place. Andrews v. State ex rel. Eskew, 618 P.2d 398, 400-401 (Okla.1980). No review of that ruling has been sought here as it was in Henderson v. Maley, et al., 806 P.2d 626 (Okla.1991), a case arising out of the same election.
. Oklahoma County uses a paper (really cardboard) ballot in its elections in conjunction with an electronic counting device. After the ballot is filled in by a voter it is inserted into the device which scans it and automatically reads and registers the choices made by the voter. Essentially, the electronic device takes the place of human counters. At least as early as 1979 we noted the use of these or similar type machines in Tulsa County in the case of Helm v. State Election Board, 589 P.2d 224, 229 (Okla.1979). It appears these types of devices have been authorized for use on a statewide basis after a unitary system of election administration has been implemented by the Secretary of the State Election Board. See 26 O.S.Supp.1989, § 21-101.
. The executed judgment of the trial judge does not contain a finding concerning the 587 spoiled ballots. However, a letter ruling of the trial judge dated November 27, 1990 contains the finding. Our review of these two documents lead us to conclude the omission of the finding from the executed judgment we have been provided was one of mere oversight. On the letter ruling the spoiled ballot matter was listed by the trial judge first under the category of irregularities he thought cast serious doubt as to the mathematical certainty of the vote. In all there were seven such irregularities listed. On the executed judgment there are six irregularities listed which correspond to the final six irregularities on the letter ruling. The six irregularities are placed on the executed judgment after alphabetical headings F through K. In the paragraph directly below listed irregularity K the trial judge makes his finding that said irregularities, “E through K” (emphasis added), are the ones casting serious doubt as to the mathematical certainty. Obviously, paragraph E was meant to contain the 587 spoiled ballot issue, the first issue contained in the letter ruling. Even if we are wrong in such conclusion we will assume for the purpose of our opinion the issue is before us and we will decide it.
. The evidence as to the 87 unregistered voters consisted primarily of testimony of election board officials and its records. Jackson argues the evidence made clear many people register right up to the deadline before an election with one of the over 600 precinct registrars in Oklahoma County and it is not unusual for these registrations to be transmitted to the county offices weeks or even months after an election. He, therefore, asserts evidence limited only to records of the county board was insufficient to show the 87 people were unregistered. In his view contestant was required to check the records of the precinct registrars to see if one or more of the 87 were, in fact, actually registered, but their registrations had simply not been transmitted to the county offices. In view of our ultimate ruling here that contestant did not prove his case in any event we need not definitively decide whether a contestant can make out a prima fade case involving unregistered voters by presenting only evidence from the county election board records. We will assume he can.
. Keltch contains dicta to the effect we may have had a different view if we were faced with a situation similar to the one here (i.e. more ballots cast than signatures in the poll book, etc.), rather than the situation there (more ballots issued than signatures in a poll book). Id. at 909-910. To the extent Keltch contains such dicta we disapprove it here. The point of Keltch and the one we reiterate here is that failing to obtain a signature in a poll book is of a directory nature. Failure to obtain a signature alone is insufficient to taint the votes cast in excess of the signatures without some additional evidence the votes themselves are illegal. To rule otherwise would potentially disenfranchise legal voters on mere speculation and void a result which does truly reflect the will of the electorate because of an omission by election officials. Very simply, the failure to obtain signatures in 66 instances where over 172,000 votes were cast cannot overcome the presumption in favor of the reported precinct results in the amount of 66 votes. Such a conclusion sustains our oft repeated view that every presumption in favor of the validity of an election will be indulged [See Cooper v. Dix, 771 P.2d 614, 617 (Okla.1989) ], and, generally, an election not clearly illegal will be upheld. Id. and Keltch, supra at 911. Without some minimal indication, not found in this record, the 66 votes were cast by illegal voters or were in some other respect invalid, we refuse to turn the signing of a poll book into a mandatory requirement, the omission of which results in an invalidating sanction for votes cast in excess of the number of signatures.
. In addition to the scanner being able to "read” ballots marked with the specialized pen, the evidence disclosed a number 2 pencil and any relatively dark pen mark could also be read by the scanner, depending on its color.
. According to the voting machine division supervisor by definition a not defined ballot is one not recognized by the machine for a variety of reasons and one that is returned or "kicked back" to the voter.
. To the extent the trial court’s findings regarding head errors or scanning problems were meant to refer to something else besides the not defined readings, such as possibly malfunctioning of certain machines or reports concerning repairs of machines during the election, the evidence in this record is simply insufficient to sustain a finding that any machine malfunctioned in such a manner to support a conclusion that voted ballots were read incorrectly or not at all so that it would be impossible to determine with mathematical certainty who won this election. This may be the reason the trial court in his judgment only said the head errors and scanning problems "cast serious doubt as concerns the mathematical certainty of the election”, rather than making a specific finding these matters were sufficient to prove it was impossible to determine with mathematical certainty who was entitled to be issued a certificate of election as required by 26 O.S.Supp.1990, § 8-120(2).
. The zero tape is supposed to be run at the beginning of the election day before any votes are cast to show that no votes are registered on the electronic voting device scanning or counting mechanism.
. Although the trial court made no specific findings concerning them Smith raises here certain irregularities which were the subject of evidence below (e.g. certain reporting forms from precinct officials to the election board secretary indicating questionable handling of voted ballots and one polling place being closed with people still in line to vote). We have reviewed all such matters and view the documentation supporting same to be somewhat ambiguous. Smith called no precinct officials to support or explain the documentation. However, even assuming the irregularities occurred Smith wholly failed to present sufficient numbers which would taint this election result.
.In view of our disposition of this matter we have no occasion to rule on Jackson’s assertion that certain allegations of Smith’s petition alleging irregularities should have been stricken by the trial court as not being specific enough. See generally Otjen v. Kerr, 191 Okla. 628, 136 P.2d 411 (1942).